A light scattering investigation of the sodium dodecyl sulfate–lysozyme system

Dynamic and static light scattering measurements have been made on lysozyme solutions at 25 °C in 0.1 M phosphate buffer, pH 6.88, in the presence of sodium dodecyl sulfate (SDS). The concentration of SDS has been varied over a wide range (0–0.2 g/ml). It is found that under these conditions both SDS micelles and lysozyme(Lys)–SDS complexes coexist. Addition of lysozyme at constant SDS concentration leads to formation of more lysozyme–SDS complex. The translational diffusion coefficient of the complex increases with SDS concentration. It is also found that two lysozyme molecules are associated in the protein–surfactant complex.